Ship-guidance bybtek



April 24, 1926 1,666,897

.1. H. HAMMOND, JR

SHIP GUIDANCE SYSTEM Filed April 27. 1922 2 Sheets-Sheet 1 avwwntoz April24, 192s. v v 1,666,897

. J. H. HAMMOND, JR

sax? 'efimmcs SYSTEM Filed April 27. 1922 I 2 She'ejts-Sheet 2 Jo/m Hays fia/vmand, .11: 3391.3 abtmq 46 7 mainde'r of the cable is thrown overboardto float in the water. The specific gravity of milling oni; flies oFFic-E.

more, moccasins. mammal.

This "invntibn reiats to 1 systems of sig;

ticular y to systems for ii'idicatiiig the relative positions of movable bodies wherebydesired relative positions maybe maintained;

- to provide means for'maintaining such po- I by the transmitter positioned as indicatedat 11 and also with a transmitter positioned.

sitions independent of fog or darkness; to indicate variationsin speed of a leading body so that the speed of the following body may be adjusted accordingly; to provide signailing currents having a plurality of characteristics each indicating a --va riation in a different spacing of the bodies; and to provide other objects as will appear from the:

following description" taken in connection with the accompanying drawin s.-- I

Referring to the drawings,'Figure'1 shows a plurality of vessels in single file; Figure 2 shows the radiant energy transmitting means; and Figure 3 shows the radiant energy responsive means.

Referring to Figure 1, there is represented a series of movable .bodies comprising an indeterminate number of vessels in single file. As shownthree vessels'are illustrated, a leading vessel. 10 being provided with means for transmittingradiant energy p0 sitioned as indicated at 11, an intermediate vessel such as 12 being rovided with means 13 responsive to the ra iant energy emitted as indicated at 14 corresponding to the transi ted, g uctor 23 extending the length of mitter shown at 11, and rearmost vessel 15 provided with means 16 responsive to the radiant energy emitted by the transmitter of the next forward vessel such as 12.

Each transmitter for transmitting the radiant energy comprises a trailer 20' (see Fig; 2) which may consist of a flexible electric cable I suitablyI insulated and protected by a sheath whic ductor. The forward end 21 is suitably se- "cured to an appropriatecable terminal- (not shown) on the respective vessel, and the rethereon in a well known manner 'for main-- taining said remainingportion in the water at a predetermined depth. The free end of the cable 20 is provi ed with a grounding sleeve -22 to which is connected an insuby radiant energy and more par-1 may be a metallic 0011-.

the cable. Substantially midway of the the sleeve 24 to theship. The intermediate sleeve 24-is positioned at a predetermined distance from the ship from which it is trailed, this distance corresponding'to the minimum desired spacing of an adjacent pair of ships of the train. The outer sleeve 22 is spaced apart from the ships by the length of-the cable 20, this being equivalent to the maximum desired spacing of an adjacent pair of ships. Thus the zone26, extending from the sleeve 24 to the vessel end 21 of. the cable comprises the danger zone which it is desired that the next successive vesselof the train of vessels -indicated in Figure 1 shall not enter. L o

For selectively connectingl into circuit the conductors 23 and 25 respectively,'there are provided circuit closers such as contact springs 30 and 31. Closure of either of these keys connects the respective conductor to the secondary of a transformer 32, inductively coupled to the circuit of a source of audio-frequenc alteliigating current 33. One pole of t e seco ary winding of the transformer 32 is grouhded to the rame of the ship.

- Generator 33 may enerate radio frequency current, in whic case, microphones 60 and 61, or an other modulating device, may be used in p ace of keys 30 and 31.

For receiving radiant energy on the trailing vessel, there is provided on each a pair of receiving loops 40 and 41 symmetrically positioned on the right (starboard) and left (port) sides of the vessel respectively. These loops each consist of conductors, preferably insulated, wound in a continuous looparound a supporting frame of suitable size; Theftwo loops of a vessel have the same structural characteristics, such as size,

number of turns and size of wire, so that negative end of the filament by a predetermined amount. The voltage of this battery determines the point on the characteristic curve of the device at which the tube shall be operated. For audio-frequency reception tube 44 is used as an amplifier. For

radio frequency reception battery 54 is adjusted so that the tube functions as a detector. A plate battery 55 maintains a potential between the plate 51 and the negative end of the filament to render the plate 5.1 an anode with respect thereto. An indicating device, such as a receiver 50 is providedin the plate circuit, responsive to oscillations therein. In order to render audible in the telephones 56, signals of radio frequencies, when not modulated by microphones and 61 but interrupted b keys 30 and 31 a source of variable radio requency is shown at 39 connected to an inducing coil 37, which is in inductive relation to transformer 43, thus forming the well known heterodyne receiver. The frequency of the source 39 is adjusted so as to differ from that of the incoming signal by an amount of say 1,000 cycles, thus audible beats will be heard in the telephones 56.

In operation, each transmitter is operated either automatically, as by a clockwork (ill mechanism, or continually in a well known manner manually bya member of the crew of its respective shlp, while eachreceiving device is attended by a member of the crew of its ship. The transmitting and receiving stations are operated in pairs, a transmitter of one ship and the receiver of the next following ship forming a pair, and since the several pairs of a train of ships are identical in-operation, a description of the operation of one such pair will suffice for all.

The generator 33 may be driven in any appropriate manner and supplies power to transformer 21. Assuming that audio frequency signaling is desired and that first key 30 is closed, a current will flow in the circuit; frame of the ship. secondary winding of the transformer 32 in which an alternating current is induced, key 30 conductor 23, sleeve 22, the return being through the body of water in which the ship and trailer 20 floats. As the result of this flow of-current, there will be set up an alternating magnetic field around the entire cable trailer 20. The lines of force of this alternating magnetic field cut the coils of the receiving loops of the next following ship. Assuming that the switch 42 is in the position shown in Figure 3, so that the coil 40 is in circuit an alternating current will be induced in the circuit; loop 40, blades of switch 42, through condenser 38, which is varied for loudest signal, of the transformer 43. A secondary current of the same frequency is induced in the other winding of this transformer, and this current alternately increases and decreases the normal grid potential of the device 44. Impulses corresponding thereto, but of greatly amplified value flow in the plate circuit andthrough the indicating receiver 56, producing a tone therein. Y

The operator who is listening to the signals now throws the switch 42 to its opposite closed position. This makes the other loop 41 effective in the same manner, and a tone is again produced in the. receiver 56.

If the following ship is directly above the cable 20, the intensity of the received signal will be substantially the same in the two positions of the switch 42, since the loops 40 and 41 are equi-distant from the cable. If, however, the course of the ship has been diverted, the loops 40 and 41 are not equidistant from the cable, then the signal from the loop nearer the. cable is the louder. The course of the vessel may then be diverted towards the cable until sounds of the same intensity are again received in both positions of the switch 42. When the guiding ships course is changed the action is the same as if the course of the; following ship has been diverted, and the following vessel is steered until sounds of the same intensity are heard. Thus the course of the following vessel will correspond to that of the leading vessel.

Should'the spacing of the vessels be increased, as by acceleration of the guiding vessel or b de-acccleration of the following vessel, so that the distance between the loops 40 and 41 and the free end of the preceding cable is increased, the signal will become weaker, in both positions of the switch 42. The operator will then issue instructions to have the speed of the vessel increased.

Should the spacing of the vessels be decreased as by de-acceleration of the guiding vessel or acceleration of the following vcssel, the signals produced upon closure of the key 31 will be detected. These signals are caused by a current in the circuit; frame of the ship, secondary winding of the transformers 32 in which an alternating current is induced, key 31. conductor 25, sleeve 24, the return'being through the body of water. Thus an alternating magnetic field is set up around that portion of the cable between the guiding vessel and thesleeve 24 (zone 26, Fig. 2). The lines of force of this alternating magnetic field cutthe coils-of the receiving loops whenever the key 31 and switch controlled by ke characteristic di I. fers from that circuit which key 30 connumber of movable b darkness. a

I to a-tralling ship, either b bykey 30 may be key 31 interm 1ttent; or that controlled by trols, either electricall both in time element or For example, t e current controlled continuous'and that by key 30 may be interrupted to send dots every ha f second, and that by key 31,-say, ten dots er second; or, one 1 current maybe modu ated by a voice current corresponding to the. sentence.-,You are getting too near and the other may. be unmodulated;

or other characteristics maybe varied to produce a differentiated result.

As the followin vessel approaches too closely, it approaches or passes the sleeve 24 and enters the zone 26. The loop which" happens to be connected through the switch 42 is now out by the alternating magnetic fieldof the zone 26 and a current of the character controlled b the key '31 energizes the transformer 43. his current is' heard in the receiver 56 as before and indicates that the vessel has a proachedgtooclose to the next vessel ahead Orders are thereforeissued to reduce s eed until the original sound is heard indicating that the'following vessel is between the sleeve 24 and 22.

This mode of operation is followed throughout the train of vessels, and thus a variable course and apredetermined spacing may be held to b an indeterminate ies, even in fog or When radio frequency current is employed at the transmitter the o eration of the sys-- tem is similar to that; escribed above for audio-frequenc signaling, except the receiving vacuum tube 44 is caused to function as a detector instead of amplifier by a readjustment of. say batte 54. If the radio signals be sent by manipulation of keys 30 and '31 then the hereinbefore mentioned heterodyne receiver should be placed in operation by the starting'of the variable frequency source 39. Thislis notnecessary, if modulated radio frequenc current is employed, althou h it is desirable if the beat note can be a justed to and maintained at zero frequency. For producing distinguishing characterlstics for each oftwo radiations from cable 20, a tunin fork ma be made to vibrate in front of eac microp one, 30 and 31, the pitches of said tuning forks being widely different.

Messages canbe sent'from a leading ship voice or the telegraphic code by employing the system hereindescribed;

. Having thus described inventiomjwhat claim and desire-"to secure by Letters Pat- '1.- -In a s a'llingi m,- ra plurality of ships in pre: eter'min formation, a pluralships in predetermined for transmitting radiant energy' from each .means positioned on eac cept the first-selectivelyresponsive to said radiant energy including means for differentiating one from another of said series and ity of variously characterized means for emitting radiant energy from each of the ships-except the last, andmeans responsive to said radiant energy positioned on each ship except the first. i

2. In a signalling system, a plurality of of the ships except the last, comprising a plurality of I variously characterized antennae, means responsive to radiant energy positioned on each ship exceptthe first.

3. In a signalling system for a train of movable bodies, means trailed by each of saidbodies except'the last-adapted to emit radiant'energ indicating means positioned on each of said bodies except the first selectively responsive to said energy including means for determining the relative intensities of .said energy received from different.

directions to indicate divergence of the course of the respective body from that of the. adjacent preceding bod and means sitioned on each of such bodies excepting the last for emitting radiant energy having impressed thereon modulations for indicating approximately the distance separating the respective body from the preceding adjacent body. 4. In a signalling system for a train of movable bodies, means trailed by each of said bodies except the last for emitting. a pluralit ferent c aracteristics respectively, indicating means for determining the relative intensities of said ener received from diverging directions to in icate divergence of the. course of the respective body from that of the adjacent preceding body.

sists in the step of-trailing a floating cable behind the ship for indicatingthe shipsjpO- sitio'n, to following ,ships. and emitting radiant ener from a portion of said cable for indicating danger in the zone adjacent said portion.

- 6. In a system of communication between ships, means carried behind the leading ship for transmitting signals to a following .ship comprising a floating cable, and'mea'ns including a portionof said cable for emitting a danger signal to thefollowing. ship in the zone adjacent said portion.

7. In a signalling system for a train of of said bodies ex-' formation, means of series of radiations having dif- 5. A method of ship control which: consponsive to one, of said series for determin ing the relative intensities of said energy received from different directions to indicate divergence of the courseof the'respective body from that of the adjacent precedingbody, and including means differently responsive to another of said series according to the distance separating the respective bodyirom' the preceding ad acent body.

8. In a si nalling s 'stein, a'plurality of movable bodies in predetermined formation, a source of radio frequency oscillations of predetermined high frequency,- a lurality of variously characterized means f br emitting radiant frequency oscillations from each of said ships except the last, a corresponding plurality of variously character- 'ized modulators for modulating said predetermined high frequency, additional means for operatively connecting each of said modulators to one, of said emitting means, and means responsive to said radiant energy positioned on each ship except the first.

' 9. In a system for signalling from a movable body, a cable towed the body, means for impressing signal energy upon themedium surrounding the body comprising having a conductor extending the full length of the cable-and a second conductor extending less than the length of the cable, and means; for modifying the energy in accordance with a signal.

10. In asystem for signalling from a movable body, means for impressing signal energy-upon the medium surrounding the body comprising a cable towed by the body having aconductor extending the full length of the cable and a second conductor grounded at a point intermediate the ends of the cable, and means for modifying the energy in accordance with a signal.

11. In a system for signalling from a movable body, means for emitting radiant energy therefrom comprising a pair of spaced members towed atdiflerent distances from said body,'and means for modifylng said energy to produce a signal.

. 12. In a signalling system for movable bodies, a guiding vessel, a uided vessel, an insulated conductor of prefetermined length grounded at its-outer extremity towed by the guiding vessel, 9.- second insulated conductor of relatively greater "length grounded at its outerextremity towed by the guiding vessel, means for impressingone character ofenergy upon one of said conductors, additional means for impressing -difierently characterized energy upon the otherof. said conductors, and receiving device posi-- tionedupon the guided vessel and responsive to energy emitted from said conductors.

13. In a signalling system, the combina-' tion of a plurality of movable bodies in preguided and a guiding 'vessel, a plurality ofsources having relatively different signal characteristics, a plurality of conductors of relatively different length each grounded at its outer extremity and each connected at its inner extremity to one of said sources of energy for emitting differently characterized' radiant energy. respectively, said conductors being towed behind the guiding vessel, and a receiving device on the guided vessel selectively responsive to the differently characterized emitted energy.

signature.

JOHN HAYS HAMMOND, JR.

so u

. In testimony whereof I hereunto afiix my 

